How can your supermarket habits hurt you? Imagine your insurance company perusing your shopping records. Then you get a letter in the mail: Gee Jim, I see you've been packing on the Ben & Jerry's Chubby Hubby lately. Cool it on the lard, fatboy, or we'll double your insurance premiums.
Or the divorce attorney for your soon-to-be-ex wife clocking how much beer you buy in order to persuade a judge you're a bad influence on the kids.
This isn't just theoretical. In the most infamous case, a Washington state firefighter was arrested for arson in 2004 because his Safeway Club Card was used to purchase the same brand of firestarter used to set the blaze. (He was later released.)
Of course, we're not just talking about shopping records. Companies like Rapleaf specialize in combining this shopping data with publicly available information (such as voter registration and property records) and tidbits culled from your Web surfing history, Facebook, and more.
Rapleaf offers the usual assurances about keeping this data private and anonymous. Then again, it was outed last fall by the Wall Street Journal for collecting a host of highly personal and personally identifiable information about some of the people in its database, including their political and religious beliefs and their attitudes toward tobacco, gambling, and adult entertainment (not to mention pork products). Rapleaf was also one of a few dozen companies "inadvertently" passing Facebook and MySpace IDs to ad networks, in violation of those services' privacy policies.
You'll have to forgive me then if I don't exactly take comfort in Rapleaf's assurances. The only thing keeping data miners like Rapleaf from handing over your entire personal dossier is that nobody has slapped them with a court order or written a big enough check yet. It's bound to happen eventually.
Don't want to be followed around the Piggly Wiggly by companies like Rapleaf? Use a loyalty card filled with false information and pay cash when possible. You also might want to lay off the bacon and buy more fruit -- just in case.
Do data miners worry you? Post your thoughts below or email me: firstname.lastname@example.org.
This article, "The difference between Microsoft and Google -- it's not what you think," was originally published at InfoWorld.com. Track the crazy twists and turns of the tech industry with Robert X. Cringely's Notes from the Field blog, and subscribe to Cringely's Notes from the Underground newsletter. For the latest business technology news, follow InfoWorld.com on Twitter.